The present invention relates to a process and apparatus for applying a chemical to a textile substrate. More particularly, the present invention is directed to a process and apparatus for applying a dye to a continuous length of a textile substrate such as carpet, and such as made from a natural polyamide material, such as wool, or a synthetic polyamide material, such as nylon.
Conventional systems for dyeing textile substrates such as carpet involve the application of the dye, by various processes, to the carpet, followed by passing the dyed carpet through a steamer to achieve fixation of the dye to the carpet. Conventional steamers have to be of a length sufficient to enable treatment of the dyed carpet for a sufficient time to achieve fixation. The residence time of a given carpet section generally is from approximately 4 to approximately 15 minutes. Since the carpet passes through the dyeing machine at a relatively high speed, for example up to approximately 30 yards a minute and even higher, these steamers must have a quite long length, even when the steaming path undulates. Typically, steamers are of a length of 100 to 300 feet, and even longer. It will be apparent that the cost of providing and operating such steamers is quite high. Thus, the energy costs to maintain steam in such large enclosures is high. Furthermore, maintenance costs as well as initial capital costs are high. Even further, the cost of the large amount of factory space required for such steamers is high.
Furthermore, various attempts have been made to improve conventional dyeing procedures, and specifically to improve the quality and reproducibility of dyeing operations.
One system, the so-called "Otting" system sprays the dye onto the carpet with the aid of air and then heats the dyed carpet. This system still however requires the use of a steamer.
Another system, the so-called "Artos" system, passes the carpet through a bath of dye liquor heated to a boiling point temperature. After the carpet passes through the dye bath, the carpet is rinsed and then dried.
Another system is the so-called "PRINTAIRE" system wherein dye is applied to the carpet by creating a foam which is applied to the carpet. The thus dyed carpet then is passed through a steamer.
All of the above prior art systems are expensive, both in initial investment and in operating cost.